Compositing pyroxylin



July 4, 1933. F, c. CLOSE LQGS@ COMPOSITING PYROXYLIN Filed Juiy 15. 1951 7W@ i $505@ @5% A125 @bho/:Man l Patented July 4, i9@ i @France noun o. enosnjor naw Your; n', Sr,

oorarfosrrrne rvnonvnrn Application filed July 13, 1931. Seria1`No. 550,363.

The present invention has for its object the provision of a novel and improved method of utilizing a previously formed colorbody in connection with a plurality of op- 5 positely facing sheets of pyroXylin or, as it' the transfer of said color-body by laying one face thereof against a rst pyroXylin sheet and the other for the transfer of said color body to another pyroxylin sheet by laying the opposite face of the color-body against said second pyroxylin sheet. While for convenience the sheets aforesaid are herein referred to as pyroxylin sheets, it will be understood that the invention is applicable not only to nitrocellulose sheets, such,

for example, as Celluloid, but also to cellulose acetate sheets, and all sheets formed mainlyof a cellulose derivative.

The resulting multi-ply pyroxylin sheet or the like may be described as a pyroxylin sandwich having buried therein, and between the two pyroXylin sheets commonly employed, a film or layer constituted by the color-body. Said color-body ilm or layer functions not only as a decorative agency but also as an important participant, ac-

cording to the present invention, inthe bonding means which holds the pyroxylin plies in secure and permanent cohesion all over. The color-body, considered as a decorative coadjuvant, is protected on both sides lby sheets of pyroXylin actually or substantially integrated therewith, and is visible through `the pyroXylin sheets on one or both 4sides where such sheets are transparent. By the term color-bodyas used herein is meant a previously formed picture or design, or

legend or other indicia; and by the word color is meant not only a true color, such as red, yellow, blue, orange, white and so on, or a combination thereof, but also black, or

` a combination thereof with any true color or colors, as gray or brown.

Such a pyroXylin sandwich (or composited pyroXylin, as it is known in the art) is in large demand commercially, but heretoforeV its successful production has' been troublesome and unsatisfactory, if not impossible; for one thing, because the wastage due to rejects and spoilages has necessarily resulted in a high cost factor, and for another thing, because the bond between the individual pyroxylin sheets making up the composite has been diicult to attain even with highly skilled operatives, which bond, even when apparently set up to some extent at the immediate conclusion of the compositing, is even then comparatively weak and generally unreliable.

One of the troubles encountered in previously attempting; tocomposite Celluloid or pyroxylin andan interposed color-body has been due to the fact that before the two pyroxylin sheets on opposite sides of the colorbody can be made to enter into mutual adhesion at those places beyond the limits of the color-body and to enter into adhesionwith the opposite faces of the color-body, said sheets must be so softened that the color-body is spoiled; that is, the adhesions just referred to apparently cannot be brought about by bringing the oppositely facing surfaces of the pyroxylin sheets to mere tackiness, but, instead, only are accomplished by reducing sald surfaces and the pyroXylin material therebeyond to a jellylike consistency. rllhe pressure accompanying the heat which brings about this jellying causes a measurable iow of the pyroXylin material in a direction transverse to the line of pressure; and the components or elements of the color-body naturally follow the jelly flow, thus breaking up the color-body as well as causing color distortions, blurrlngs and the like. This result is aggravated where the compositing is being attemptedby heat and pressure relative to two pyroxylln sheets on one of which has previously been deposlted the color-body by ordinary or direct lithography or other printing; that is, where the color-body is not previously formed i the sense that it has not been previously l1 hographed or otherwise printed or spread n a paper sheet or other temporary carri, for subsequent transfer therefrom to the lastmentioned pyroxylin sheet. The probable reason for this is that the color-body, when directly printed on a pyroxylin sheet, is then necessarily brought into contact with and spread over the pyroxylin material of this sheet without having previously been spread on the temporary carrier of a transfer picture and there dried and then set or degreened at least to some extent, and perhaps to the extent described and claimed in my copending application Serial No. 518,912. Therein, a setting or degreening period for the color-body is specified as probably not less than a minimumof three days at ordinary room temperature and at any rate at least until a heat and pressure transfer of the color-body to a sheet of celluloid will cause the color-body to become so tenaeiously secured to said sheet as to preclude removal of the color-body therefrom by abrasion without bodily removing some of the Celluloid maferial.

The reason for mentioning such a completely unsatisfactory method of attempting successful pyroxylin compositing as includes a first or early step of lithographing or otherwise directly printing the color-body upon a first pyroxylin sheet, is to make plainer the nature of the problem involved, and to explain the present invention as fully and Clearly as possible, as Well also as to emphasize unmistakably the fact, or my present conviction at least, that successful pyroxylin compositing cannot be attained without including the ancillary step of forming and drying a color-body on a paper sheet or other suitable temporary carrier before attempting to apply said color-body to the pyroxylin material. In other words, as the present invention is now understood, the process of transfer or socalled decalcomania is a necessary element thereof; in order that the color-body may, as aforesaid, be one formed previously to its attempted 'attachment to the first pyroxylin sheet, and on a paper sheet or other suitable temporary carrier-this last desirable in view of the thinness and fragility of the color-body per se and the degreening time-lapse preferred between the time of creation of the spread color body and the moment when it is to be attached to said first pyroxylin sheet by heat and pressure as one step of the method of the present invention.

This heat and pressure step just referred to, involving as it does the deliberate avoidance of a cellulose lacquer (by which is meant a Celluloid as well as a cellulose lacquer) as an initial interponent between the color-body and the first pyroxylin sheet as Well also as any initial softening of the pyroxylin material of said sheet by a solvent or solvents, is exceedingly important, and, rather paradoxically, in order to prepare the way for the later use of such a cellulose lacquer or of a solvent or solvents (or of an equivalent softener of the pyroxylin material) as the 'transfer, applied as an interponent between the other side of the color-body and the second pyroxylin sheet preparatory to the second heat and pressure step.

The discovery underlying the present im- 'provement is the more surprising, at first consideration at any rate, in View of the fact that as previous workers in the art have attempted to use solvents or special adhesives for the purpose of transferring, by heat and pressure or otherwise, a previously formed colorbody to the first pyroxylin sheet, the maintenance of the color-body in its complete integrity has uniformly been found to be impossible; the probable explanation being that a successful transfer of said previously formed color-body to a pyroxylin base material requires, as mentioned hereinabove, that the pyroxylin, directly lying against the color-body being applied to a sheet thereof, be not jellified or otherwise exist as a stratum of material in dissolved or relatively free flowing condition-unless the color-body, during the attempted bonding therewith of the pyroxylin material, is somehow held and anchored against relative shift in its own plane of all the various color-body components or elements. This last proviso is added, as probably satisfactory explaining the present improvement. Extensive experiments, at any rate, apparently verify the soundness of the same.

The present invention, then, (as the same is now understood), provides, more specifically, a method of compositing pyroxylin material which involves (a) transferring a previously formed color-body to a first pyroxylin sheet by heat and pressure and without the use of a softener, (b) thereby obtaining an interpenetration or other strong prelimi- .nary bond between the pyroxylin material and the substance of the color-body all over the latter sufiicient to hold and anchor all the components of the color-body against relative shift in its own plane, (c) thereafter softening, and even if necessary dissolving somewhat, (by the use of a softener as aforesaid, to wit, for example, a cellulose or celluloid lacquer or other suitable cement or solvent, and preferably by the use of a softener comprising pyroxylin liquified by a superabundance of amyl acetate or other solvent),

llO

aeiaeeo 0 or coating with said softener or a similar softener, the color-bod thus anchored, and (d) applying heat an -pressure to the two sheets of pyroxylin and the'interposed colorbody and the softener or softeners applied secure and permanent bonding of the colorbody with the second-mentioned or last-applied pyroxylin sheet, and at the same time, apparently due to a driving of the softener orsoftened pyroxylin material of said second-mentioned pyroxylin sheet, through the color-body and into the first-mentioned pyroxylin sheet, to secure a stronger bond than before between the color-body and said first-mentioned sheet; all without in any way dlstorting or rupturing or blurring or otherwise disturbing the color-body in any portion thereof.

ln view of the paragraph last preceding, the reason for the proviso hereinabove given will now be understood; if it be also pointed i out that the temporary paper or other suitable carrier for a previously formed colorbody, which carrier is not detached until the color-body has been secured in a spread condition to a selected base material, is commonly provided with a mucilaginous4 film or the like between said carrier and the colorbody for facilitating easy removal of said carrier after a transfer has been eected upon moistening or heating said film; said film coacting with said carrier to allow the colorbody to be initially formed and to hold the Acolor-body spread and thus maintain its integrity prior to detachment of the carrier, but the color-body itself being of inadequate strength and toughness to restrain the vario us components of the color-body from relative shift in its own plane in response to pulling and other stresses arising in ordinary handling. So that, by the present invention, the color-body is protectively held spread on its carrier before application to a first Y pyroxylin sheet, the color-body is secured to said sheet by the first heat and pressure step in a way to maintain the color-body protectively held spread during and after removal of said carrier, and consequently the color-body is protectively held spread by said first pyroxylin sheet in a way to protect the components of the color-body against disruptive relative shift during the final or true compositing step, that is, during the addition of a .second pyroxylin sheet, even where, as here, pyroXylin material being thus composited with the color-body is jellified and heat and pressure are employed for the 'step last-mentioned.

The present invention will be more clearly understood from the following descripas Just explained, thereby to accomplish a.

tion, when taken in connection with the accompanying drawing illustrating a preferred way of carrying out such invention, in which Fig. l is a transverse section taken through the first pyroxylin sheet and a previously formed color-body laid thereon to be transferred thereto by heat and pressure; this color-body being shown as part of a built-up multi-layer structure including said colorbody and, as the parts are seen in this view, an overlying mucilaginous layer, and above said layer an ordinary paper sheet constituting with said layer the temporary carrier for the color-body.

Fig. 2 illustrates, similarly, said pyroxylin sheet and the color-body, after the application of the first heat and pressure step; the color-body being now bonded to the pyroxylin along the line indicated by small crosses, and the paper carrier and inucilaginous layer having been removed by moistening these and stripping away the paper and washing off the mucilaginous material.

Fig. 3 is a transverse section taken through the parts as shown in Fig. 2 and also through the second applied pyroXylin sheet, and showing a coating of softener as aforesaid, all in readiness for the application of the second heat and pressure step.

Fig. 4 illustrates likewise in transverse section the finished composited article, the color-body now being on opposite sides bonded securely and permanently to both the pyroXylin sheets.

Similar reference characters refer to similar parts throughout the several views of the drawing; which drawing is largely schematic, certain thicknesses being more or less exaggerated relative to others, and the bonds or interpenetrations of the color-body with the pyroxylin material on opposite sides thereof (Fig. 4L) being only diagrammatically or suggestively indicated.

Referring now to the drawing `more 1n detail:

At 5 is indicated the first pyroxylin sheet, and at 6 the second pyroxylin sheet.

At 7 is indicated the multi-layer structure preferred to be employed for safe creation and subsequent safe handling of the colorbody formed previously to a transfer of the latter to pyroxylin sheet 5. Said lstructure is here made up of a color-body 8, a paper backing or carrier 9, and a deXtrin or other suitable mucilaginous layer or film 10.

The line of crosses marked 11 in Figs. 2 and 3 is intended to represent graphically the preliminary yet secure bond attained between the upper part of the first pyroXylin sheet 5 and the lower face or part of the color-body 8, as the result of the first heat and pressure step, pursuant to the invention.

This first heat and pressure step is applied with the parts assembled as shown in Fig. l;

as between hollow steam-filled metal plates in say a hydraulic press. A temperature of approximately from 175 degrees to 200 degrees Fahrenheit, and a pressure of approximately between 450 and 500 pounds per square inch, are now recommended for best results; it also being recommended that the pyroxylin sheet be one previously cured, at least to the critical point disclosed and claimed in my said copending application. Therein, it Vis prescribed that a celluloid sheet to which a color-body yis to be successfully bonded should be cured or dried out to a state orcondition such that when the sheet is then shaped to any desired configuration out of the fiat, for instance, to make a hemisphere, this hemisphere or the like will not subsequently measurably work or distort out of shape.

Thereafter, the paper or equivalent 9 is stripped ofi', as by wetting the same to dissolve the layer 10, or otherwise suitably removed; as is the material of said layer 10.

This leaves the parts as illustrated in Fig. 2. Next, either substantially at once, or at any later time desired, the new article is completed as a pyroxylin composite by arranging the parts as shown in Fig. 3 and as previously described, that is, with a coating of lacquer or solvent or an equivalent softener 12 inter-- posed between the color-body 8 and the second pyroxylin sheet 6. The parts are illustrated in Fig. 3 as though said layer l2 always necessarily exists as distinctly such at the time of thus assembling or stacking the various sheet elements; this, however, is primarily for purposes of simplifying and clarifying the drawing. As a matter of fact, it is not believed to be particularly desirable to have said layer 12, at this stage of the proceedings, exist `as, a layer-element having a distinctly marked off line of sepa-ration from the pyroxylin sheet 6. On the contrary, so far as the invention is now understood, it is recommended that the softener applied (graphically indicated by the layer l2) be wapplied only over the lower face of the pyroxylin sheet 6, and be allowed to merge with or become absorbed by the pyroxylin material of said sheet, to some extent at least, so that said softener will actually be present as a partially or completely jellilied subdivision or stratum in the bottom of said sheet 6, before said sheet 6 is laid over the color-body 8 at the face thereof exposed as in Fig. 2 preparatory to the second heat and pressure step.

In any event, as I now understand the invention, the situation at this stage to be arranged. is the interposition, between the color-body 8 and the second-applied pyroxylin sheet 6, of a softened pyroxylin mass or of a pyroxylin softener; that is, there should be applied to the face of the color-body 8 as exposed in Fig. 2, as a feature of the second heat and pressure application to sandwich the color-body between the two pyroxylin sheets, a softener either already wholly or partially jellifyingly incorporated in the pyroxylin material of the sheet 6 or in readiness to become thus incorporated in said pyroxylin material during said second heat and pressure application.

Finally referring to Fig. 4, it will be seen that the layer 12 of Fig. 3 (whether or not assumed to be a jellified stratum of the pyroxylin sheet 6 as applied in said Fig. 3), has, as such, disappeared. Yet in one sense (as I understand the invention), said layer is still nally present, that is, has partially passed through the color-body 8, incidentally probably partially to jellify the upper portion of pyroxylin sheet 5, and now lies partially above the color-body and partially below the same, with the color-body interpenetrated on both sides thereof with the underlying and overlying pyroxylin sheets 5 and 6 (as attempted to be graphically illustrated by the central dot and dash lines in Fig. 4 and the liner cross-hatching irregularly splayed beyond said' dot and dash lines) the net result being, at any rate, that subsequent to the second heat and pressure step the color-body and the enclosing pyroxylin sheets are all securely and permanently interbonded and the color-body is not ruptured, blurred or injured in any way. This bond is such, for instance, that neither pyroxylin sheet will split away from the other or from the color-body even as the result of repeatedly alternately curving or ruilling the finally composited sheet structure out of its normal plane; which curving or ruiiiing, it will readily be understood, gives rise to strong disruptive stresses due to tendencies exerted by the two pyroxylin sheets to shift edgewisely in opposite directions.

Considerable particularities of description, as to materials, dimensions, pressures, temperatures, capacities, utilities, theories and preferances, may have been herein indulged in, but it will be understood that these statements are not in any way to be taken as definitive or limitative of the invention. That is to say, fit is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense. f

It is also to be understood that the language contained in the following claims is intended to cover all the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language,

with the definitions hereinabove expressly or pyroxylin impliedly incorporated, as broadly as is consistent with the prior art.

I claim:

l.. The method of compositing pyroxylin, which involves spreading a color-body over a pyroxylin sheet, preliminarily securing said body to said sheet by the aid of heat and pressure, applying a softener for pyroXylin material as an interponent between a second pyroxylin sheet and the face of said color-body opposite to the face thereof lying against the first pyroXylin sheet, and, with the color-body sandwiched between the two pyroXylin sheets, applying heat and pressure to the elements thus stacked; A

2. The method of compositing pyroxylin, which involves providing .a color-body previously printed from lithographicink and previously dried, securing such color-body in various portions at one side thereof to a pyroxylin sheet by the aid of heat and pressure, applying a second p-yroxylin sheet against the opposite side of said color-body while interposing softened pyroxylin vmaterial between the color-body and the side of said second sheet remote from said colorbody, and driving said softened vmateria-l through the color-body and against the second pyroXylin sheet, thereby, while employing said color-body as a decorative agency, utilizing the same finally as a participant in the action of said softened pyroXylin material to attain secure and permanent bonding together of the two sheets between which the color-body is buried.

3. The method of compositing yroxylin, which involves spreading a colorody over a pyroxylin sheet and preliminarily attaching said color-body to said sheet by the aid of heat and pressure, thereby to insure that 'the color-body in dried condition will be suciently secured to said pyroxylin sheet to preclude relative shift of the color-body parts in the plane of the color-body in response to movements of a jelliiied pyroxylin stratum extended facewisely of the colorbody in direct abutment thereagainst, thereafter applying jelliied pyroylin *material as such a stratum as an incident to the application of a second pyroxylin sheet on the side of said color-body opposite to the side thereof secured as aforesaid to the first pyroxylin sheet, and applying heat and pressure transversely of such stratum to an extent suicient to cause parts of said stratum to tend to have movements, thereby to bond the color-body to both pyrogxylin sheets by interpenetrations of parts of said color-body and the pyroxylin material of both sheets.

4. llfhe method of compositing pyroXylin, which involves spreading a color-body over a sheet and preliminarily attaching said color-body to said sheet by the aid of heat and pressure, thereby to insure that the color-body in dried condition will be suciently secured to said pyroXylin sheet to preclude relative shift of the color-body parts in the plane of the color-body in response to movements of a jellilied pyroXylin stratum extended facewisely of the colorbody in direct abutment thereagainst, thereafter incorporating jelliied pyroxylin material as such a stratum as an incident to the application of a second pyroXylin sheet to said color-body, and applying heat and pressure simultaneously to all the elements aforesaid, such pressure being exerted transversely of said stratum to an extent sufcient to cause parts of said stratum to tend to have such movements, thereby to bond the colorbody to both pyroXylin sheets by interpenetrations of parts of said color-body and the pyroxylin material of both sheets without deleterious damage to said color-body as a decorative adjunct to be finally viewed through one of said pyroxylinsheets.

5. The method of compositing pyroxylin, which involves transferring the color-body of a lithographed transfer-print by heat and pressure to the upper face of a first pyroxylin sheet in unsoftened condition, thereafter applying a second pyroXylin sheet over said color-body with said second sheet softened on its under side to carry there a'softened stratum, and thereafter subjecting the thus stacked elements to heat and pressure.

6. The method of compositing pyroxylin, l

which involves transferring by heat and pressure a previously dried color-body printed from lithographie ink to the upper face of a first pyroxylin sheet in unsoftened condition, applying a softener to a face of a second pyroxylin sheet, laying the softened face of said second sheet against the upper face of said color-body, and applying heat and pressure to the elements thus stacked.

7. The method of compositing pyroXylin, which involvestransferring the color-body of a lithographed transfer-print by heat and pressure to the upper face of a lirst pyrozry-4 lin sheet and securing said color-body relatively impermanently to said sheet, applying a second sheet over the upper face of said color-body while interposing softened pyroXylin material between the face of the color-body and a face of one of said sheets, and by the aid of heat and pressure and said softened material integrating permanently said color-body and the two sheets. v

8. The method of compositing pyroXylin, which involves transferring the color-body of a lithographed transfer-print in dried condition by heat and pressure to the upper face of a first `pyroiiylin sheet and securing said color-body relatively impermanently to said sheet, applying a second pyroxylin sheet over the upper face of said color-body, and

employing a softener for pyroXylin material,

and heat and pressure, permanently to integrate said color-body and the two sheets.

9. The method of compositing pyroXylin, which involves transferring the color-body of a lithographed transfer-print in dried condition by heat and pressure to the upper face of a first pyroxylin sheet and securing said color-body relatively impermanently to said sheet, applying a second sheet over the upper face of said color-body, and employing heat and pressure and a thermoplastic mass in jellified condition between one of said sheets and the color-body, thereby permanently to integrate said color-body and the two sheets.

l0. The method of compositing pyroxylin, which involves transferring the color-body of a lithographed transfer-print by heat and pressure to the upper face of a first pyroxylin sheet and securing said color-body relatively impermanently to said sheet, applying a second sheet over the upper face of said colorbody While interposing softened pyroXylin material between a face of the color-body and a. face of one of the sheets, and by the aid of heat and pressure permanently integrating said color-body and the two sheets.

11. The method of compositing pyroxylin` which involves providing a previously spread and dried color-body and a plurality of pyroXylin sheets in ordinary cured condition, securing said color-body to one of said sheets while the latter is in said condition, by the aid of heat and pressure, and thereafter securing said color-body and the sheet lastmentioned to the other pyroxylin sheet by the aid of heat and pressure incident to the interposition between said color-body and one of said sheets of a pyroXylin solvent, said solvent being added after the aforesaid securement of said color-body to the first-mentioned sheet.

12. The method of compositing pyroxylin, wh'ich involves providing a previously spread and dried color-body and a plurality of pyroxylin sheets in ordinary cured condition, securing said color-body to one of said sheets while the latter is in said condition by the aid l of heat and pressure, applying -a pyroXylin solvent to one of the two sheet structures now thus provided, applying the other pyroxylin sheet against said color-body to provide a stack with the pyroxylin solvent and the color-body buried therein, and subjecting the stack to heat and pressure to secure the lastmentioned pyroxylin sheet to the color-body.

13. The method of compositing pyroxylin, which involves providing a previously spread and dried color body including lithographie 'ink and also providing a plurality of pyroXylin sheets in ordinary cured condition, securing said color-body to one of said sheets while the latter is in said condition by the aid of heat and pressure, applying a pyroxylin solvent to one of the two sheet structures now thus provided, applying the other pyroxylin sheet against said color-body to interpose both the color-body and said solvent between the two pyroxylin sheets, and applying heat while compressing the stacked elements.

14. The method of compositing pyroxylin, which involves transferring by heat and pressure a previously formed color-body to a first pyroxylin sheet in ordinary set condition, thereby to obtain a preliminary bond betweensaid sheet and the substance of the color-body all over the latter sulicient to anchor all the components of the color-body against relative shift in the plane of the color-body; thereafter softening the face of the pyroXylin sheet next to be applied to the exposed face of the color-body; and applying heat and pressure to the two sheets of pyroXylin material and the interposed color-body,

thereby to accomplish a secure and permanent bonding of the color-body with the second-applied pyroxylin sheet and at the same time to accomplish the same bonding of the color-body with the first-mentioned sheet of pyroXylin material by subjecting thc lastmentioned material to the action of said solvent by passage of the latter through said color-body.

Signed at Brooklyn, in the county of Kings and State of New York this 27th day of April A. D. 1931.

FORD C. CLOSE. 

